Recuperatcmt tube tdsj



233390& RECUPERATOR? STRUCTURE Graham Edgewoodg 1 41.; assignor to: Amsler Morto- Corporation, Pittsburgl h a corporation of e Thisrinventionrelates generaliy to industrial heat ex- Chhg'ers; kn'wn asree'uperators and morearticularly t a recperato-' tuhetie structure that conducts i the hot gases -from* the-'mrnaceehamber through 'a recuperator to thestack to effect" a heat exchange;

The-princ'ipal *object* of this-*invention is the previson of particular style of tubular tile structurethat provides' increased surface area for-prodcinga moreefiicient transfer ofheat and also provides additinai physical strength to thetube `tileitself. i

,The rincipal object of this invention is to improve the thermoefiiiency' in the-heattransferenee' from' the hot gase's ilwngdown these-flue ppes to the air owing past the'ut'side thereof intothefhrnace: The partieular structures as disclosed in this application increases-the efficieucy of heatttansference by reason of the fact that they are provided 'with lngitudinall y disposed fins or ribs on the inside iofltle ttbe andtf'ann'tlarrihsson the outside. &structure of this character permitsthecylindrieal ,crosssection: ofithe tube to be reduced in. size-:which increases thefiequercy ofheat transferencm. Again, the ribs in the bore of the tubes are Iongi'tudinallyand in the same direction as the flow of theg'ass througli tlfe tubes, and they have attenden'cy to direct and. strengthen -z this flow; The annular ribs on the outside of the flue tubes are likewise in the same direction as the path of air as it continues back and forth upon rising through the recuperator. The annular ribs on the outside of the tube also provide an increased surface area together with a reduced cylindrcal section of the tube which also increases the heat exchange from the inside to the outside of the tube.

The flue tubes may be constructed with the crosssection substantially cylindrical or octagonal or any other suitable form. In the past, octagonal flue tubes have been employed and they are equally adapted to contain the longitudinally extending ribs in the bore and the annular external ribs in the same manner as that of the fiue tube with cylindrical cross-section.

Owing to the fact that the actual cross-sectional area of the cylindrical portion of the tube may be reduced in thickness, in view of the increased area supplied by the ribs, and a greater heat transference is provided in each tube with substantially the same amount of material and the same space employed with the recuperator, which is' a material advancement over that of the previous structures.

Other objects and advantages appear hereinafter in the following description and claims.

The accompanying drawings show for the purpose of exemplification, without limiting the invention and claims thereto, certain practical embodiments of the invention wherein:

Fig. l is a view in vertical section of the recuperator tile structure assembled in a refractory chanber embodying the principals of this invention.

Fig. 2 is a large perspective view of a fine tube comprising this iuvention.

United States P tc i 21 t Fig. 3 is a detailed sectional view, showing thedisposition of the inner and 'outenrihs of the-titre' tube:-

Fi'g. 4is' alarge'detailed vew of'the flte bloch which is employed in the -horzontal corse otthe reetiperator employing a ribbedtub'e -strtctue i Fg. 5` is a plan view of' an' octagonal fornr of tube, comprising this'invention.

Referring' to the-drawing& each ot the t ile structures: making up` the recuperator is-nade or a -material eapable of withstandihg a ve-y high waste gas heat: and'also capable of withstanding a high degree' of-"thermo shock an still maintain its' shape. and is -capablie of*supporting tie recupera'tor structure the'reabove: i

The recuperator tile structure-is layed-'witliiii the-te` cuperator refractory' chamher 'r'closed by retraewr' side walls z and 3; In the arched roof teontains-the passage 5, through which the-waste-gases are withdrwit' -fron'r the furnace chamber;

The bottom of* therecuperator-is provided witlra bridge wall 6, designed to support the recuperator tile structure within the chamber 1.' Thebridge wall isp'rovided a series of vertical openingsflthat are aligned with the"` vertical flues of'the recuperat'ortile structure for the put pose of conducting the waste gases from the-r'ecuprtot to the passage 8,: to' an additionat h'eat exehangersy or* to a stack as the case may be. j

The-horizontal courses of the reeuperator tile-:structure nay'be constructed ena plurality of dtferent'types oftile members s'ueh as illustrated in U;*S-;` Letters Patent- 2,09'3,402 and 2`,574,738 A flue hiock ltl stteh 'as-il lust ratedirr Fig. 4, is-octagonai in shape and may be ro zontal Courses containingsthe air; Theserecesses ate shapedsin a mannentorreceive*tha-vertical tubilarsectiit oftthe flue pass sucli astill ustratedat15;tand-shown-:spes cifically in Fig; 2. The intermediate' blocks have-arecess' both sides and the rihs should match theri bsof thei-u bular flue tile.,

The tubular flue tile 15 is provided with a substantially cylitdrical section as indicated 'at 16 and which has on its inner face or bore a series of inwardly extending ribs 17 and that extend longitudinally of the tube and which may be straight or follow a spital path as desired. However, the ribs 17 are in the direction of the flow of the hot gases down through the flue tubes 15. e

The external portion of the cylindrical flue tube 15 is provided with a series of annular ribs 18, which are spaced apart and are parallel to the flow of air as it proceeds back and forth across these several passes in traveling from the lower to the upper end of the recuperator. The air is conducted through the passageway 20 and travels horizontally to the opposite end of the first pass then upwardly through the opening such as indicated at 21 where it returns back through the second pass upwardly through the openings 22 to the third pass, from thence,

the air passes upwardly through the openings 23 and 24- so that it may flow back through both, next two horizontal s passes, and travel upwardly through the openings 25, 26, and 27, so that it may return through the last two horizontal passes, and being discharged through the passageway 28 and 29 at the upper end of the recuperator, from whence it flows to the furnace.

As previously stated, the recess 14 in all of the tlue blocks are shaped to receive the ends of the tubular fiue tile members 15 and they are likewise provided with a series of inwardly extending rib members 30, which are matched in number and size with, and made algned with rib member 17 of the matching flue tile. Thus, the whole of the end face of the tile structure is supported from the bottom of the bridge wall 6 to the top of the recuperator structure, as shown in Fig. 1.

The underside of the intermediate flue blocks are likewise provided with' a' cavity for receiving the tops of the subjacent flue tile. The blocks at the topand the bottom of the recuperator, have only one recess, since they do not support a flue tile of the same structure on tner opposte faces? i At the top ofthe tile structure an additional or extra horizontal course 31 is added by placing the same on the top of the horizontal seal course made by the upper block members 32. However, the top course 31 is not cemented to the course in a manner that all the other tile blocks are cemented together. This top course includes an additional set of short tubes 33 that are cemented to the top course 32 and extend upwardly into the chamber 1. These may be or may not be shorter than the tubes 15, however, they are placed on 'top of the rccuperator for the purpose of gathering and collecting resdue from the furuace which becomes hardened, and when it reaches the tops of the tubes 32, the top layer 32 is usually removed and replaced before the residue has an opportunity to descend through the tubes and' choke the passageways.

Flue structure, such as illustrated at Fig. s similar to that disclosed at 15 in Fig. 2, with the exception that the flue 35 is provided with an octagonal cross-section and the outer ribs 36, and the vertical inner ribs 37 follow the general cross-section of the octagonal tube. With structures of this character the recess seat 14 and the blocks must be likewise changed to fit the structure of these vertical tubes.-

Regardless of whether the shape of the tube s cylndrical or octagonal, the air, in traveling back and forth through the horizontal passes, is guided and directed by the annular ribs 18 and the gases which pass downwardly through the flue tubes are guided in their path by the ribs 17. Since the wall 16 of the tubes can be materially thinner than that of the present tubes, the heat transference is materially greater in this structure than in any other known tile structure, and at the same time, the strength of these tubular fiue structures is not reduced, as the total cross-sectional area remains substantially the same when including the ribs 17, which provides strength in supporting the load of the tile structure. Again, the annular ribs 18 will provide an increased reinforcement for each I 4, r of the vertical tubes, thereby strengthening the 'structure physcally. i I claim:

l. Heat transfer tile structures for the constructon of recuperators comprising a refractory member having an annular wall with an opening therethrough, a plurality of spaced ribs integral with thewall of the refractory mernber and projecting inwa'rdly into said opening, said ribs extending longitudinally of the wall forming said opening to aid in guiding gas es passing therethrough, the crosssectional area of the ribs providing additional 'load carrying'support to enable 'reduction of the thickness of the annular wall to increase the heat exchange through the refractory member. i

2. The structure of claim 1 characterized in that said refractory member has a recess surrounding said vertical opening to receive a tubular flue member with matching inwardly projecting ribs.

3. The structure of claim l characterized in thatsaid refractory member has an elongated tubular wall structur'e, and which also includes a plurality of spaced annular reinforcing rib means encircling the exterior of said tubular refractory member and spaced from the ends thereof for guiding gases flowing therepast, increasing the heat transfer thereof.

4. The structure of claim 3 characterized in that said tubular wall structure is circular and the inwardly projecting ribs are circumferentially spaced about the inner wall thereof. V

5. The structure of claim 3 characterized in that said tubular wall structure is octagonal and the inwardly projecting ribs are circumferentially spaced about the inner wall thereof.

References cited in the file of this patent UNITED STATES PATENTS 1,296,o58 Fe'dders Mar. 4, 1919 2,463,997 Rodgers Mar. 8, 1949 2,574,738 Graham et al. ;A.. ..7 Nov. 13, 1951 FOREIGN PATENTS 446,107 France Nov. 27, 1912 

